§ 2.1505 Test instrumentation and equipment.  


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  • (a) Receiver (field intensity meter). A calibrated field intensity meter (FIM) with a frequency range of 30 to 1000 MHz is required for measuring radiated emission levels. This instrument should be capable of making peak measurements with a bandwidth of 100 kHz.

    (b) Spectrum analyzer. Spectral measurements are to be made with a spectrum analyzer with a minimum resolution bandwidth no greater than 10 Hz. The video filter, if used, should have a bandwidth wide enough so as to not affect peak readings. A linear video output is desirable for performing measurements of modulation characteristics.

    (c) Storage oscilloscope. Measurements of modulation characteristics are to be made using a calibrated storage oscilloscope. This instrument is to be DC coupled and capable of manually triggered single sweeps.

    (d) Frequency counter. A frequency counter with an accuracy of at least 5 parts per million is required for measuring the carrier frequency.

    (e) Signal generator. A calibrated signal generator with an output of at least 75 mW at 121.5 and 243 MHz is required for generating a reference signal for site calibration.

    (f) Antenna. Radiated emissions are to be measured with calibrated, tuned, half-wave dipole antennas covering the frequency range of 30 to 1000 MHz.

    (g) Temperature chamber. Tests which call for subjecting the EPIRB to temperature levels other than the ambient temperature are to be performed in a temperature test chamber which can be adjusted to stable temperatures from −20 to +55 °C. This chamber is to be of sufficient size to accommodate the EPIRB under test.

    (h) Vibration table. A vibration table capable of vibrating the EPIRB with a sinusoidal motion is required. The table must be capable of varying the frequency of vibration either linearly or logarithmically over a range of 4 to 33 Hz with maximum peak amplitudes of up to 2.5 mm.

    (i) Salt fog chamber. A chamber capable of producing salt fog at a temperature of 35 °C for 48 hours is required. This chamber is to be of sufficient size to accommodate the EPIRB under test.

    (j) Drop test facility. A facility which will permit dropping an EPIRB from a height of 20 m into water is required. The water must be deep enough so that the EPIRB will not touch bottom when dropped.